Multisection combustion grate with lateral sealing means



Sept. 3, 1968 R. HOLSTEIN ET AL 3,399,662

MULTISECTION COMBUSTION GRATE WITH LATERAL SEALING MEANS Filed March 16, 1967 INVENTORS RICHAQD HOLS TE/N HERBfRT V016 T United States Patent "ice 3,399,662 MULTISECTION COMBUSTION GRATE WITH LATERAL SEALING MEANS Richard Holstein, Denkendorf, and Herbert Voigt, Esslingen, Germany, assignors to Haniel & Lueg G.m.b.H., Dusseldorf-Grafenberg, Germany Filed Mar. 16, 1967, Ser. No. 623,742 Claims priority, application Germany, Mar. 16, 1966, H 58,814 Claims. (Cl. 126--176) ABSTRACT OF THE DISCLOSURE The disclosure relates to multisection combustion grates and particularly to such grates which are useful for burning refuse and the like which constitute inferior and highly ballast-rich fuels. The principal feature of the disclosure is the provision of circular sealing disks at laterally opposite ends of each grate section, these sealing disks cooperating with stationary sealing means, such as the walls of a combustion chamber, to provide a maze sealing against entry of combustion air into the combustion chamber around the grate section pivoting means, and to prevent exit of combustible gases from the combustion chamber around the grate pivoting means.

In accordance with the disclosure, each disk may be arranged not only to form a seal for its associated grate section but also to overlap an adjacent grate section. The disks may be mounted in common recesses in the inner surface of the combustion chamber wall, or may be mounted in individual recesses, the recesses conforming in outline to the disks positioned therein, Alternatively, each disk may be arranged in a separate cup-shaped stationary sealing member which is in sealing relation with the wall of the combustion chamber.

Background of the invention In the burning of garbage and other refuse, constituting inferior and highly ballast-rich fuels, it is not only essential that the fuel air be moving but also that it be loosened or broken up. For this purpose, combustion grates have been developed, for use in garbage burning plants, and these grates comprise grate sections arranged in series in the direction of travel of the fuel. The grate sections have a circular sector profile and can be oscillated about transverse axes.

In using combustion grates of this type, difficulties are encountered because, due to the swinging or oscillation of the grate sections, a lateral sealing of the grate sections against the later-a1 entry of combustion air or the lateral exit of combustion gases is not possible in a simple manner such as is possible, for example, with a moving grate.

In combustion plants where the combustion air is under a pressure of, for example, several hundreds of millimeters of water column, it is advisable to provide means to avoid jets of flame at the sides of the grate. Such jets of flame cause air to be forced through the sides of the grate producing slags on the refractory lining of the combustion chamber.

Summary of the invention The invention is directed to combustion grates and, more particularly, to an improved multisection combustion grate including oscillatable sections and provided with novel sealing means against entry of air and exit of combustion gases laterally of the combustion chamber.

In accordance with the invention, a satisfactory screening of the grate sections against such air entry and combustion gas leakage is provided by means of disks at 3,399,662 Patented Sept. 3, 1968 the laterally opposite ends of the individual grate sections. The circumference of these disks is a circular arc concentric with the oscillation axis of the associated grate section, and the disks, together with a stationary cover, form a maze screen. Such a screen is formed, for example, by setting the lateral sealing disks, which are oscillatable with the grate section, into recesses in the lateral walls of the combustion chamber and with very little play. Thereby, by using a simple and consequently operation-ally safe means, it is possible to ensure that the combustion air is distributed approximately uniformly over the width of the grate and enters the latter only from below.

In comparison with known combustion grates with drives for the oscillatable grate sections, the lateral sealing disks of the present invention do not require any substantial additional expense if the oscillation drive of the grate sections is also effective on the lateral sealing disks. It is not necessary to discard the arrangement of the swing drives at the outside of the walls of the combustion chamber, provided that each swing drive acts on the pivot pin or axle of the lateral sealing disks which support the grate sections at laterally opposite ends, these pivot pins or axles being concentric with the swinging axes of the associated grate sections. Essentially, the invention has the same advantages for all combustion grates utilizing oscillatable sections and independent of the fuel involved.

Accordingly, an object of the invention is to provide an improved combustion grate for burning garbage and other refuse constituting inferior and highly ballast-rich fuels.

Another object of the invention is to provide such a combustion grate including several grate sections which are oscillatable about axes extending transversely of the grate and further including sealing means sealing each section at laterally opposite ends thereof.

A further object of the invention is to provide such a multisection combustion grate in which the lateral sealing means are disks disposed in recesses in the walls of a com-bustion chamber.

Still another object of the invention is to provide such a combustion gate which is simple and operationally safe, as well as ensuring the stream of combustion air being distributed substantially uniformly over the width of the grate and entering the grate only from below.

Brief description of the drawings For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.

In the drawings:

FIG. 1 is a side elevation view of a portion of a combustion grate illustrating several oscillatable grate sections and the associated lateral sealing disks;

FIG. 2 is a partial plan view of the combustion grate shown in FIG. 1 and the associated sealing disks;

FIG. 3 is a view, similar to FIG. 2, illustrating a modified form of grate section; and

FIG. 4 is a vertical sectional view of a grate illustrating a modification of the maze scaling for the grate sections.

Description of the preferred embodiments In the embodiment of the invention shown somewhat schematically in FIG. 1, oscillatable grate sections 1 alternate with relatively stationary bridging grate sections 2. Grate sections 1 are swin'gable about transversely extending axes 3, with the range of swinging or oscillation being indicated by the arrow 4. The drive for effecting such oscillation may comprise, for example, fluid pressure actuators 5 whose pistons are connected to the respective grate sections 1.

a 3 As may be seen in FIG. 2, the oscillatable grate sections 1 as well as the stationary bridging sections 2 are subdivided. At their front ends, as viewed in FIGS. 1 and 2, each grate section 1 has associated therewith, or constructcd as a parat thereof, a sealing disk 6. These disks are set in a recess 7 in the side wall 8 of the combustion chamber, this recess having a circular arc outline concentric to the axis 3. In the embodiment of FIGS. 1 and 2, each oscillation axis 3 is arranged beyond the circular arc outline of the associated grate section 1, as by being at the center of the circular arc outline. The associated disk 6 consequently overlaps the adjacent stationary grate section 2 as well as the next succeeding movable grate section 1. This will be apparent from an inspection of FIGS. 1 and 2. In recess 7, disks 6 form a maze constituting a resistance to the fiow of combustion air and which resistance is substantially greater than that of the passages within the grate surface. Thus, this maze forms a seal preventing the formation of lateral jets of combustion gas.

Referring to FIG. 2, each of the drive mechanisms includes a pivot arm 9 having a free end connected to the associated fluid pressure actuator 5, and having its fixed end secured to the pivot pin 6' of the lateral disks 6. Thus, disks 6 are oscillated along with grate sections 1. In order to transmit high torques, which are necessary with particularly wide grates and when burning difficult industrial refuse, disks 6 may comprise fireproof cast iron with a steel support construction inserted therein. This facilitates transmission of the drive power from the actuators 5 to the oscillatable grate sections 1, and furthermore is particularly advantageous with respect to heat protection.

In some multisectioned grates, including oscillatable grate sections, the axis of oscillation is not located as shown in FIGS. 1 and 2. Referring to FIG. 3, the axis of oscillation 3 of the grate sections 1 may be arranged within the circular sector-shaped outline or side elevation of the grate sections. In such case, the sealing disks 6 may be set individually into respective recesses 7' in the side wall 8 of the cumbustion chamber.

However, it is not necessary that the sealing disks be set into recesses in the wall of the combustion chamber. FIG. 4 shows an arrangement in which each of the lateral sealing disks 6 is disposed in a stationary sealing cover 10 fixedly mounted on the inner surface of the side wall 8 of the cumbustion chamber. Cover 10 closely conforms to and embraces disk 6, and also forms a maze sealing which has the same efiect as the embodiments of the invention shown in FIGS. 1, 2 and 3. Whether the embodiment of FIG. 2 or the embodiment of FIG. 4 is selected for any particular installation, is dependent upon the prevailing conditions, taking into consideration the construction of the side wall 8 of the combustion chamber and the combustion chamber arranged above the grate.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invenaion, it will be understood that the invention may be embodied otherwise without departing from such principles.

- -What is claimed is:

1. In a combustion grate, particularly for plants burning refuse, and having plural grate sections arranged in series in the direction of fuel conveyance, with each grate section having, in side elevation, a circular sector profile including acircular arc andbein-g mounted for oscillation about an axis transverse to the direction of fuel conveyance; means for screening the grate sections against lateral'entry of combustion air, said means comprising, in combination, disks arranged laterally of each grate section, the circumference of each disk being a circular arc concentric with the axis of oscillation of the associated grate section; and stationary sealing means cooperable with said disks and forming a maze sealing therewith.

2. A combustion grate, as claimed in claim 1, including a combustion chamber in which said grate is arranged, said combustion chamber having side walls; each of said disks being set in recesses in said side walls.

3. A combustion grate, as claimed in claim 1, in which each of said disks and its associated stationary sealing means overlaps at least one immediately adjacent grate section.

4. A combustion grate, as claimed in claim 1, in which said plural grate sections include relatively stationary grate sections alternating, in the direction of fuel conveyance, with said oscillatable grate sections; each of said disks overlapping the immediately adjacent relatively stationary grate section.

5. A combustion grate, as claimed in claim 4, in which each of said disks also overlaps the immediately succeeding oscillatable grate section.

6. A combustion grate, as claimed in claim 1, including drive means operable to oscillate said grate sections; each drive means being operatively connected to the associated grate section through the disk associated with the latter.

7. A combustion grate, as claimed in claim 1, in which each of said oscillation axes is concentric with said circular sector profile but positioned outside said circular section profile.

8. A combustion grate, as claimed in claim 6, in which each disk has a pivot pin concentric with the axis of oscillation of its associated grate section; said drive means being operatively connected to the associated pivot pins.

9. A combustion grate, as claimed in claim 1, in which each of said oscillation axes is disposed within said circular sector profile.

10. A combustion grate, as claimed in claim 1, including a combustion chamber in which said grate is mounted, said combustion chamber having side walls; said stationary sealing means comprising circular housings each mounted on a combustion chamber side wall and each closely embracing a respective disk to form therewith said maze sealing.

References Cited UNITED STATES PATENTS 1,460,618 7/1923 Stimmel 39 1,586,963 6/1926 Budd 126176 X 3,057,309 10/1962 Turner et al. 126176 X CHARLES J. MYHRE, Prin'zary Examiner. 

